CVE-2011-0411

Status Candidate

Overview

The STARTTLS implementation in Postfix 2.4.x before 2.4.16, 2.5.x before 2.5.12, 2.6.x before 2.6.9, and 2.7.x before 2.7.3 does not properly restrict I/O buffering, which allows man-in-the-middle attackers to insert commands into encrypted SMTP sessions by sending a cleartext command that is processed after TLS is in place, related to a "plaintext command injection" attack.

Debian Linux Security Advisory 2346-1 - Several vulnerabilities were discovered in ProFTPD, an FTP server. ProFTPD incorrectly uses data from an unencrypted input buffer after encryption has been enabled with STARTTLS, an issue similar to CVE-2011-0411. ProFTPD uses a response pool after freeing it under exceptional conditions, possibly leading to remote code execution.

Ubuntu Security Notice 1113-1 - It was discovered that the Postfix package incorrectly granted write access on the PID directory to the postfix user. A local attacker could use this flaw to possibly conduct a symlink attack and overwrite arbitrary files. This issue only affected Ubuntu 6.06 LTS and 8.04 LTS. Wietse Venema discovered that Postfix incorrectly handled cleartext commands after TLS is in place. A remote attacker could exploit this to inject cleartext commands into TLS sessions, and possibly obtain confidential information such as passwords.